$I will draw you a diagram. Edit: Updated diagram for clarity.$
$Step 1: Resolve each of the momentum components in the$\; x \;$and$\; y \;$direction.$
$Step 2:$
$Let's consider N$10$E first. We have in the$\; x\; $direction$\; 20\cos 80 \; $kgm/s$,\; y \;$direction$\...